Pressure core barrel



Dec. 17, 1946.

B. W. SEWELL PRESSURE CORE BARREL Filed June 15, 1942 2 Sheets-Sheet 24. 9Z JMNVENTOR.

Patented Dec. 17, 1946 ES PAT 2,412,915 PRESSURE CORE BARREL Benjamin W.Sewell, Tulsa, Okla., assignor to Standard Oil Developm ration ofDelaware ent Company; a corpo- Application June 15, 1942, Serial No;447.047

5. Claims. (Cl. 255- 72) The present invention is directed to a wirelinepressure core barrel.

The principal object of the present in ention is the provision in adevice of the character described of an improved valve actuating means..Other objects of the present invention are to simplify construction of adevice of the character described and to impart more positive action tothe parts thereof.

Further objects and advantages of the present invention will appear fromthe following detailed description of the accompanying drawings, inwhich i Fig. 1 is a front elevation, partly in section, of the upperpart of one type of pressure core barrel according to thepresentinvention in coring position;

Fig. 2 is a similar view of the lower part. of the same core barrel inthe same position;

Fig. 3 is a similar viewof the upper part of the same core barrel withparts in position for the recovery therefrom of the trapped constituents; and I Fig. 4 is a similar view of the lower part of the samebarrel in the same position.

Referring to the drawings in detail, numeral I designates the upperportion of the drill collar of the drill string, and 2 the lowerportion. The two are screwed together, and mounted in the joint betweenthem is aring 3 having an internal diameter which, for the purpose ofdescription, will hereinafter be referred to as X. Secured to the lowerend. of the bottom section 2 of the drill collar is the drilling head 4which is provided with rotarycutters 5 and a central passage 6 forreceiving the core. Drillingmud passages 1 connect the interior of thedrill collar with the seats of the rotary bits.

Fixed in place in the lower section of the drill .collar is the corebarrel assembly, consisting essentially of a pressure tube 8 in whichthe core receiving barrel 9 is slidingly arranged. Attached to the lowerend of the pressure tube is a valve body consisting essentially of asleeve Ill having an external diameter such as to make a sliding fitwith X. The upper end of the sleeve is in screw thread engagement withthe lower end of the pressure tube. The intermediate position of thesleeve is cut away to form two opposed windows H and two opposed arms l2having flat inside faces. Set in the cut away portion in such a way asto protrude is a ball valve [3 having a central passage adapted to passthecore receiving barrel 9. The ball is seated on one side on the innercircumference of the sleeve 10 and on the other side on the upper rim ofa liner l5. .Wlien tlie' core barrel is in its core receiving position,the. ball valve has on one side a-vertically arranged groove I! in whichis fixed a pawl l8 the finger end of which protrudes upwardly beyondtheout; side diameter of the sleeve Ill. The periphery of the latter isslotted to receive the pawl for the purpose hereafter specified. The lyspring pressed outwardly.

The upper end of the core receiving barrel carries a check valve l9which is adapted to permit the flow of fluid outwardly from the barreland prevent flow in the opposite direction. Extending upwardly from thisvalve is stem 20 which terminates in a spearhead 2 l. The upper end ofthe pressure tube 8 carries a plug 22 which has an" outside diametersubstantially less than X, but. which carries longitudinally disposedribs 23 which are of only slightly. smallerdiameter than X. The spacebetween the ribs is provided for the passage of the drilling fluid. Thelower end, of the plug 22 carries a ring 24 which is adapted to seat on.a gasket 25 carried in the annular surface provided on the upper end ofthecheck valve The upper end of the plug 22 isprovided with" an inwardlydirected lip 26 which is adapted to receive a lug 21 pivoted in a slotin the stem 20. This lug is so shaped that when the spearhead is in itslowermost position the lug is forced out ward. When the spearhead ispulled outwardly, the lug can move inwardly in the recess in the stem20. 1

The exterior of pressure tube 8 is provided with circumferentiallyspaced longitudinal leaf springs. 28 which perform the double functionofbreaki in: means and spacing means. Inuse, the entire assembly isdropped into the drill stem'. The springs 28 are so designed as toprovide suflicient friction against the interior of the drill stem'to'impede the downward fall of the assembly su'flicient to prevent it frombeing injured when it reaches the bottom.

With the parts in the position shown, the core is out and passesupwardly into the core receiving barrel. The barrel is held in suitablyspaced relation in the drill collar by spacers 28. When sufiicient coreis cut a fishing tool is dropped into the drill stem to engage the headand an upward pull is exerted on the stem 20. This draws the corereceiving barrel upward in the pressure tube until the ring 24 is seatedon the gasket 25, thereby sealing the interior of the core barrel. Itmay be observed here that as core material enters the barrel the fluidin the barrel leaves OFFICE'Q- panel is normall passes through the ring3 the lower edge of thelatter engages the finger of the valve and withcontinued upward movement of the "assembly causes the pawl to rotatearound thehoriz ontal axis. At this end there is a slot 131. in thesleeve l0 and the liner IE to receive the pawl [8. This results in thesealing of the lower end of the core receiving barrel and the assemblyis then brought to the surface.

As shown in Fig. 4, thelcollar is provided above thearms H with oppositedisposed diaphragm discs 32i These enter into the operations at thesurface when the barrel is recovered. Through one of'these discsthere isconnected a pressure measuring device 33 of the character illustrated inFigJ2 of U. S. Patent 2,243,398, issued May 27, 1941; It'may be notedthat in this case thepressure onthe outside of the disc is created byscre w-' ing iii-screw 31." To the opening covered by the other disc, isattached'a' fitting 34 in which-is arranged a plunger 35for rupturingthe disc, and to permit. the fluid contents thereof to'pass outthrougl'ia tube' 36 The'valve I3 is then opened and the upper end of the stem 20i taken off, and the core receiving barrel is withdrawn from thepressure tube.

'Itwillj be apparent that many changes may be made thespe'cificstructure without departing frolni thescope of the presentinvention.- The specific embodiment illustrated is a preferredembodiment to which the present inventioniis not necessarily limited.

The nature "and objects of the present invention having been thusdescribed and illustrated, what is claimed as'new and useful and isdesired to be secured by Letters Patent is:

1. A pressure, retaining coring assembly for bringing a; core to thesurface of the ground at'thelsa'rne pressure the core left theformation,com'prising a string of drill tubing,. a core barrel adaptedtofbe'lowered into and raised completely out of the string of drilltubing during normal drilling operations, a bit having a passage in thecenter thereof attached to, the end of the drill tubing to cut the core,the core when out passing upwardly through the passage in the bit andinto the lower end of the core barrel;

means on the core barrel to receive lifting means lowered within thedrill tubing to lift the core barrel complet'elyout of thegdrill tubingwhen coring is completed, a valve for" closing said core barrel when thelatter is lifted out of the coring position and co-acting means carriedby said valve and said drill tubing for actuating said valve.

2. A pressure retaining coring device for bringing a core to the surfaceof the ground at the same pressure the core left the formation,comprising a string of drill tubing, a core'catching assembly adapted tobelowered into and raised completely out of the string of drill tubingduring normal drilling operations comprising a casing and a core barrelslidingly mounted in said casing, a valve carried by said casing adaptedto assume an open and a closed position and to passsaidbarrel when inopen position, abit having a passage in' the center thereof attached tothe end. of. the/drill tubing to cut the core, the core when cut passingupwardly through the passage in the bit and. into the lower end of thecore barrel, means on the core barrel to receive lifting means loweredwithin the drill tubing to lift the core barrel completely'out'of thedrill tubing when coring is completed, co-acting elements carried bysaid. core barrel and said casing for causing the latter to rise after apredeitermined upward movement of the former and co-acting, meanscarried by said valve and said drill tubing to move said valve to aclosed: position during the upward movement of said casing.

3.. A coring device according'to claim 2 in which the means forreceiving lifting means'is an upwardly extending stem on said corebarrel adapted to receive a wire line and in which said core barrel andsaid casing are provided with J matingv elements for sealing the upperend of said casing after a predetermined upwardmov'e-e ment of saidbarrel relative to said casing. f:

I 4. A coring device'according'to claim 2' in which the coring. assemblyis adapted to be dropped through the drill tubing during the" drillingoperation and is provided on its outer surface with means forfrictionally engaging the inner'surface of the drilltubing to retard therate of fall of said assembly therethrough.

5. A coring assembly according to claim 1 in which the coacting meansfor actuating the valve comprises an arm' extending laterally from andmoveable with the valve normally occupying a laterally extended positionwhen the valve'is open and an abutment carried by the tubing and ar-

